Electromagnetic device



R. E. PIERCE.

ELECTROMAGNETIC DEVICE.

APPLICATION FILED DEC. 13, 1918.

1,368,288. Patented Feb. 15,1921.

INVENTOR.

. REBierce BY Z y /a- ATTORNEY when connected into a circuit of the character heretofore mentioned, and so arranged;

untrue, 5mm

PATENT OFF-ICE.

RALPH E. PIERCE, 0F LARCHMONT, NEW YORK, ASSIGN'OR Ti) AMERICANTELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

ELECTROMMNBTIC DEVICE.

7 Application meafn e bei'is, 1918.;8crla11io. 256,831.

To all it concern: I e Be it known thatI, RALPH E. Pruner: residing atLarchmont, in the county of ci'ally useful in composite telephone andtelegraph systems where com lete metallic 1 circuits are provided fprboth. ds oi messages, over the same line conductors as de-;

scribed in the copending ap lication of Osborne and Parker Serial 0.266,326, .filed December 11, 1918, assigned to the sameiassignee as thisapplication, but is obviously 1' edto a" metallic telephone circuit inaccord- 1 t me with the disclosure of the above men-' t1onedcoiendingapplications. The receivapplicable to a variety of apparatus as w'appear hereinafter. v 1

It is very desirable in a'system' of the kind mentioned for instance tohave the relay' 'winding' equally divided between the ,two'telegraphleads in order to avoid unbalancing the telephone system. Where thetelegraph circuit "is arranged for duplex working it is furthernecessary that the relay windings be in two sections having equaland-opposite magnetic effects with respect to currents from the localtransmitter, but cumulative with respect to currents from the distanttransmitter. Where the telegraph circuits are arranged 'to provide aphantom circuit it is also necessary to have the relay windings produceconnected that the electrical and magnetic effects will be balanced whensubjected to condition such as above indicated.

I have illustrated the invention as embodied in a telegraph relayprovided With eight windings, so disposed that their magnetic effectswillbe balanced for both side circuit and phantom circuit transmissionthat the resistance in each branch of the circuit is substantially thesame for current coming either from the side circuit trans-- Westchesterand State of New York, have in-/ magnetic Devices, of which thefollowing is I,

mitter or the phantom circuit transmitter. As w ll appear hereinafter,the invention-is especially adapted for a circuit of the character shownthe copending application of H. S. Osborne, Serial No. 276,485, filedFeb. 12, 1919,;ass 1gned to the same assigneo as this appl cation,though .it isobviously not limited to this use. 1 a

The invention will be more fully 'de-' scribed in connection with theaccompanying drawings inwhich'Figurel is a diagram of the electricalconnections of a relay embody ng the. invention' and Fig. 2 is aschematic-showing of the relay indicating the arrangement of thewindlngs on the fmagnet cores. I

Leads 1 and represent the op osite sides of a telegraph circuit whichmay he connecting relay is provided with eight windings,

.fourbeing connected serially in each of the -,leads 1 and 2. 7 Toprovide for duplex workin g, ,the other' ends of the two sets of relaywindings are connected to an artificialline Specification Lettersratent-I r'atented Feb. 15, 1921. M

N and the sending apparatus is bridged 7 across the center points of thetwo. sets-of relay windings as shown at 3 .and 4. This apparatus isindicated herein by batteries .5, 51 and key 6, though it is to beunderstoodthat any suitable sending apparatus may he used, such forinstance as 18 indi cated in the above mentioned applications. Toprovide for phantoming the-telephone or the telegraph circuit, theelements of the artificial line N are arranged to provide a neutralpoint 7 to which is connected 'a conductor 8 constituting one of the twophantom leads. The other lead will. connect with i a similar'neutralpoint in another telegraph circuit which may be a duplicate of that hereillustrated and which it is therefore unnecessary to show or describe indetail or to a ground'return... It will be understood that this phantomcircuit may likewise be scribed, it will be vapparent that the currentof outgoing signals may ,flow through the relay windings from either thesource 5 -5,

or the source 9--9 Current from the 'to the source."

- source 5-5 will divide at 4, traversing the two pairs of windings inlead in parallel, one portion of the current flowing out over the lineto the receiving station and the other through the artificial line N,and will return through the two pairs of windings in the lead 1,reuniting 'at 3 and thus back Current from 9-9 W111 to the source.divide at 7 between the two halves of the artificial line and pass inparallel through the four windings m' the leads land 2 re;l spectively,and return to the source 9-9 line 1', passes through the up er 'set ofrelay windings, the sendlng branc connecting 3 and 4 and the artificialline in parallel, the

lower set of relsiy windings, line 2, and back windings in eitherbranch. of the circuit, whether weconsider the current flowing from 5-5or from 9-9, must have substantially equal impedances for without thisthe currents and therefore the magnetic ef-' fects of the two brancheswill not be the same notwithstanding the fact that they may have a likenumber of turns similarly disposed upon the magnet core. a

The arrangement of windings to produce the necessary balance forsending-current from-either source 5-5 or 9- -9 is indicated in Fig. 2.The magnet is provided withtwo cores a and and on each core are fourwindings A, B, and D arranged con centrically as shown on the drawing.The outer winding A on core at is connected to the inner winding D oncore y, and the inner winding'D on core a: is connected to the outerwinding A on core 3 The next to the outer winding B on core w isconnected to the next to the inner winding C on core 1 and the next tothe inner winding C on core w is connected to the next to the outerwinding have substantially the B on core y. These connections are indi-.cated in Fig. 2 but more clearly in Fig. 1

are designated b the approprlate letter B, C, or D, wit

the character as or y suflixed to indicate the particular winding iscore on which the located.

Itwill be observed that the windings'D, being immediately next to thecores, will have a less resistance than the windings C, and so onoutward,.the windings A having the greatest resistance, same number ofturns, WhICh lS ne sary in order that they will also be clear that theassuming that vthey 1',ses,ase

may be balanced inagnetically. With windrings arranged in this manner togive substantially equalmagnetic effects, the impedance of winding Aplus the impedanceof winding D is substantially equal to the impedanceof winding Bplus the impedance of winding C. With the windings disposedon the cores and connected as above de scribed it will be observed that,whether the current be flowing from the source 5.-5 or from the source99-there is an A, a .B, a C and a D winding in each branch of thecircuit and that each branch, in either instance, has two windings oneach of the two magnetic cores. Furthermore, by connecting the Awindings to the D windings and the C windings to the B windings, asabove indicated, the halves of the branch clrcuits are likewisebalanced.

Thus for current dividing at the point 7 and proceeding over the upperand lower windings, as shown in Fig. 1, the potential drops to thepoints 3 and 4, respectively, will be the same. If it were not for thisthere would be a current flow across the sending bridge between 3. and4, whenever this bridge was closed, as it frequentlywould be.

Any current from source 9-9 taking such a course would obviouslyunbalance the whole relay. Similarly it is necessary that current fromsource 5-5 have no tendency to traverse the bridge formed by the phantomleads at each end of the line, audit will I be noticed that thearrangement shown likewise avoids any such tendency.

In a magnetic device subject to circuitconditions such as heredescribed, it is not sufiicient that the ordinary requirement of:

balance in a Wheatstone bridge be satisfied i. e. that where a, b, c,and (1, represent the four arms, but it is further necessary I' sides ofthe line will remain the same as if no relay were connected thereto.

The specific arrangement of windings hereon show is illustrative only asit will be obvious that other specific arrangements may be made withoutdeparting from the spirit of the invention.

What is claimed is:

. In a magnetic device, a plurality of windings-having substantiallyequal magnetic efle'cts but unequal impedances, a pluffrality,- ofsources of current so associated with windings that the windingsproyide" two parallel paths for current from the point' either source,and 'difierent for the two sources, the windings being so connectedtogather and to said sources of current that the total impedance in eachparallel branch for current from either source is equal to the totalimpedance in the other parallel branch for current from the same source.

2. In an electromagnetic device, a plurality of windings havingsubstantiallyequal electromagnetic efi'ects but unequal impedances, twoline conductors in each of which half of the said windings areconnected, a source of current connected to said windings at pointsintermediate their terminal connections to the line conductors and suchthat the windin provide parallel paths for said current, this windingsbeing so connected to each other and to said line conductors and sourceof current, that the impedance of the windings in the two lineconductors is the same and the impedance for current from said source inthe two parallel' branches is the same.

3. In an electromagnetic device, a plural-H 2 ity of windin s havingsubstantially equal electromagnetic. efiects but unequal impedanoes, twoline conductors in each of which half of the said windings areconnected, a source of current connected to said windings at pointsintermediate their terminal connections to the line conductors such thatthe windings provide parallel paths for said current, the windings beingso connected to each other and to-said line conductors and source ofcurrent that the impedance and magnetic effect of the windings in thetwo line conductors is the same, and the impedance and magnetic effectfor current from said source in the two parallel branches is 4 the same.

4. In an electromagnetic device, a plurality of concentric windings,each having substantially the same magnetic effect but of unequalimpedances, a second set of concentrio windings-of like charactercoiiperating therewith, two sources of current connected to saidwindings at different points and each' having difierent parallel pathsthrough said windings, the several parallel paths for ourrent fromeither source being of substantially equal impedance and substantiallyequal electromagnetic eifect.

5. In a relay, a core having two poles, a set of four windings locatedon each pole,

65 all of the windings having substantially equal magnetic effects butunequal impedances, a pair of line conductors, each line conductorhaving four of said windings connected in series therein, two from eachof said sets and so selected that the total impedance in series witheach line conductor is the same, a source of current connected to thecenter point of the four windings in each line conductor, thearrangement of the windings being such that the impedance of nection ofthe windings to each other and.

to the sources being such that the two parallel paths presented tocurrent from either source have substantially-equal impedance.

7 In an electromagnetic relay, two sets of windings, each comprisingfour windings of substantially equal magnetic efiect but an equal impeance, said windings being connected together serially, two sources ofcur rent, each connected to'said windings so as to have parallel pathstherethrough, the connection of the windings to each other and-to thesources being such that the two parallel paths presented to -currentfrom either source have substantially equal impedance and substantiallyequal ma netic efi'ect;

8. In a composite telep one and telegraph system arranged to provide ametallic circuit for the telegraph currents over the telephoneconductors, two leads connecting respectively with the twov13819113110116 0011- ductors, a relay for sald telegraph circuit havinga plurality of windings, half of which are connected in series in eachof said leads, a source of sending-current connected across themidpoints of the windings in each lead, the windings being proportionedand arranged to provide parallel paths for current from said sourceoofsubstantially equal magnetic efl'ect and substantially equal impedance.

9. In a composite telephone and telegraph system arranged to provide ametallic circuit for the telegraph currents over the telephoneconductors, two leads connecting respectively with the two telephoneconductors, a relay for said telegraph circuit having a plurality ofwindings, half of which are connected in series in each of said leads,and so proportioned that the windings in each lead have substantiallythe same magnetic effect and substantially the same impedance, a sourceof sending current connected across the Inidpoints of the windings ineach lead, the windings being pr0portioned and arranged to provideparallel paths for current from said source of substantially equalmagneticeflect'and substantially equal impedance.

10. In a composite telephone and'telegraph system arranged to provide ametallic circuit for the telegraph currents over the telephoneconductors,-two leads connecting respectively with the two telephoneconductors, a relay for said telegraph circuit having a plurality ofwindings, half of which are connected in series in each of said leads,,and so proportioned that the windings .in each lead havesubstantiallythe same magnetic efiect and substantially the sameimpedance, a source of sending current connected across the midpointsoftthe;

windings in each lead, the windings being proportioned and arranged toprovide parallel paths for current from sald source of 10. substantiallyequal magnetic Bfi BCt and substantially equal impedance, and a secondtively the windings located in each of said 15 leads.

In testimony whereof,-I have'signed my name to this specification thiseleventh day of December, 1918. I

' RALPH E. PIERCE.

